Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:NSummary
CVE-2026-4818 is a medium-severity Improper Authorization (CWE-285) vulnerability in Search-Guard Flx. Its CVSS base score is 6.8 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-4818 is an authorization bypass vulnerability affecting Search Guard FLX versions from 3.0.0 up to 4.0.1. The flaw, tied to CWE-285 (Improper Authorization) and CWE-862 (Missing Authorization), enables users lacking required privileges to perform certain management operations on data streams. It carries a CVSS v3.1 base score of 6.8 (AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N), indicating medium severity with network accessibility, high attack complexity, low privileges required, and significant impacts on confidentiality and integrity but no availability disruption.
An authenticated attacker with low privileges (PR:L) can exploit this vulnerability over the network, though it requires high complexity preconditions (AC:H). Successful exploitation allows unauthorized execution of management operations against data streams, potentially leading to high confidentiality and integrity violations, such as unauthorized data access or modification.
Mitigation details are outlined in the Search Guard advisories, including the changelog for version 4.1.0 at https://docs.search-guard.com/latest/changelog-searchguard-flx-4_1_0 and the CVE advisory at https://search-guard.com/cve-advisory/. Practitioners should upgrade to Search Guard FLX 4.1.0 or later to address the issue.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-17506
Vulnerability Data
In Search Guard FLX versions from 3.0.0 up to 4.0.1, there exists an issue which allows users without the necessary privileges to execute some management operations against data streams.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
- 11 hardening rules · 3 OS baselines
—
Mitigating Controls (NIST 800-53 r5) AI
Mandates that access-control decisions are made and applied to each request before access occurs.
Requires a tamperproof, always-invoked reference monitor that performs authorization checks.
Directly requires enforcement of approved authorizations for every access request, stopping improper or missing checks.
Limits granted privileges so that even a bypassed check affects fewer resources.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Explicitly requires defining, enforcing, and reviewing authorizations and least privilege, directly preventing missing authorization checks.
Secure SDLC practices catch and eliminate most authorization defects before release, yet a single broad outcome cannot address every design, role, and runtime facet of CWE-285.
PR.AA-01 supplies managed identities and access-request workflows that can support downstream authorization decisions, yet does nothing to enforce or verify authorization checks inside a product, leaving CWE-285 fully unaddressed by this control alone.
Network segmentation/zero-trust limits external reachability (partial prevention of exploitation) but leaves application-level authorization logic untouched, so the CWE remains fully introducible and only one facet of its risk is addressed.
PR.PS-05 blocks unauthorized binaries/DNS while CWE-285 is an in-product authorization-check defect, so the control neither prevents the weakness nor removes any of its risk.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Granular, policy-driven assignment of permissions and dynamic enforcement of those permissions prevent the incorrect or missing authorization decisions that lead to improper authorization flaws.
By requiring documented authorization rules and periodic policy reviews, the control makes it less likely that authorization decisions will be omitted or implemented inconsistently across applications.
Mapping access rights to information classification and business requirements forces correct enforcement of authorization decisions, blocking the incorrect authorization weakness at the policy and implementation stage.
Mandatory authorization checks and central records of granted rights ensure that every access attempt is preceded by an explicit decision rather than relying on missing checks.
Segregating the approval of access rights from their implementation provides an independent check that reduces the impact of missing authorization checks in the resulting system configuration.
Independent reviewers evaluate whether authorization logic matches policy, thereby reducing the window in which incorrect or missing authorization checks remain in production.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-285, CWE-862
- V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-285, CWE-862
RHEL 7 (3 rules)
- V-251704 The Red Hat Enterprise Linux operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-285, CWE-862
- V-204429 The Red Hat Enterprise Linux operating system must be configured so that users must provide a password for privilege escalation. prevents CWE-285, CWE-862
- V-204430 The Red Hat Enterprise Linux operating system must be configured so that users must re-authenticate for privilege escalation. prevents CWE-285
RHEL 8 (1 rule)
- V-251712 The RHEL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-285